'04 vz alloytec lpg/petrol problem

[mike0001]

Hey, I'm new to this forum and just need some advice...

Got a LPG conversion on my Berlina VZ Alloytec a couple of months ago.

> When i switch from LPG to petrol, car shakes severely and then turns off at red lights
> "Check powertrain" - changed oxygen sensors, however message reappears
> Whilst switching from LPG to petrol, car doesn't start sometimes or does and goes out
> Tried switching while car is off and while car is on 100km/h - same problems
> Adjusted computer - helps for one switch cycle (800km LPG, 150km petrol)


Am i doing something wrong? Any advice much appreciated.. thanks

[poweredbycng]

In order for me to assist you, I require you to answer the following questions:

1. What type of system did you have installer? I'm after brand, model and type of system (e.g. EuroGas SVI, IMPCO-BRC Sequent 56)

2. Have you been back to your installer for the vital 1,500km service / tune?

3. What is your odometer reading?

4. Have you replaced any ignition components (e.g. spark plugs, coils) lately?

5. What consumption figures are you returning?

Regards,
Dave

[Weekend Warrior]

Mine does the shaking thing to, i've taken in back to the gas place and they say that it is not the gas system but an ignition fault, the reason it shakes on gas is because gas is a harder fuel to ignite which means you'll notice the shaking alot more on gas. Next time i get a service im going to get the whole ignition system checked out. Mine also does the check powertrain warning

[poweredbycng]

Guys, what gas systems are you running?

Our VZ SV6 has been running aftermarket injected gas for over 2 years now and we haven't had a single problem with the 'gas side' of things. No check powertrain lights, and no misfires.

The first course of action to take if you are experiencing problems with LPG is to change the spark plugs. Remember that spark plugs DO NOT last as long on a gas engine so if the recommended replacement interval is 100,000km, replace the plugs at 80,000km and pay attention to the electrode gap which should be narrower for gas engines (although engines fitted with injected gas systems are much more forgiving than engines fitted with mixer-based systems).

Regards,
Dave

[mike0001]

hey,

When i run on gas, its completely fine and smooth running.
im considering it being an emissions problem, pumping the petrol through although mechanics checked it and everything, adjusts it and then it runs fine for a few hundred km's. While the car runs on petrol it shakes, gas its smooth sailing. has this still got to do with my LPG system interfering with something petrol pump related? The problems occur when i switch it back to petrol does the shaking occur and 'check powertrain' message. P.S. Found out that my LPG system isn't injection. . .

2004 Commodore Berlina VZ Alloytec 3.6L 113,000kms - full service history. Pre-Gov owned.

Thanks

[mike0001]

Forgot to add in answering Poweredbycng question.

Havn't replaced anything. Not to sure about the exact model of LPG system. Not injection i was told.

Been to mechanics more than a dozen times for check ups and tuning

Car fully serviced.

113,000Kms, 10.9-11.2L /100km average

[andyman]

you sure it isnt a vapor injected system, if it isnt it should not have been fitted to your car

[mike0001]

IMPCO system, thats all i know.

and yes, maybe its a vapour problem. im not too sure. any advice on what to look for? replace?

[andyman]

IMPCO system, thats all i know.

and yes, maybe its a vapour problem. im not too sure. any advice on what to look for? replace?

dealing with gas mate, send it to a reputable gas workshop, i try to not have much to do with it atm, untill i do a gas course

[poweredbycng]

Please post engine bay photos.

The LPG system, apart from featuring an injector cut-off, does not interfere with your petrol system, so if you're experiencing issues with petrol operation, I'd be looking at things such as your fuel pump, injectors (may need a clean) or filters. At 113,000km, I would advise you to change your spark plugs if you haven't already done so. LPG requires a stronger spark than petrol to ignite.

Regards,
Dave

[JAMS]

When inquiring about putting my October 2004 VZ acclaim on lpg some dealers told me they could without there being any problems, but others have said it is not safe since this engine was not made to handle LPG due to the type of valves fitted.

Would my car be safe to put on LPG?

Could this be the problem with the Berlina?

[poweredbycng]

When inquiring about putting my October 2004 VZ acclaim on lpg some dealers told me they could without there being any problems, but others have said it is not safe since this engine was not made to handle LPG due to the type of valves fitted.

Would my car be safe to put on LPG?

Could this be the problem with the Berlina?

Our 2005 VZ SV6 has been running perfectly on LPG for over 2 years. It is fitted with an OMVL Dream XXI system with the old injectors and has never given any problems.

All engines designed to operate on unleaded petrol have hardened valve seats anyway. Valve seat recession will occur regardless of engine or fuel type.

I'd say that if you have done the sums and they numbers add up, you should definitely go for it. If you can afford it, go for a Liquid Injection setup.

Regards,
Dave